Answer:
2x-6
Step-by-step explanation:
Answer:
y = -2x + 8
Step-by-step explanation:
The point slope form of an equation is written as
y = mx + c ...............(i)
Where m is the slope and c is the constant
Now we Know that the equation is
y + 2 = -2(x-5)
and the given points are
m= -2
x = 5
and y= -2
Putting these values in equation (i) to find the value of c
y = mx + c
it becomes
-2 = -2(5) + c
-2 = -10 + c
Adding 10 on both sides
-2 + 10 = -10 + 10 + c
8 = c
or c=8
Now we have the values of m and c
where m= -2 and c = 8
Point slope form of an equation is
y = mx + c
putting the values of m and c to get equation in slope intercept form is
y = (-2)x + 8
or
y = -2x + 8
Other method:
The given point slope form is
y + 2 = -2(x-5)
We have to change it in y= mx + c form
so solving it
y + 2 = -2x + 10
Subtracting 2 from both sides
y + 2 -2 = -2x + 10 -2
y = -2x + 8
which is same is
y=mx + c
so the required equation is
y = -2x + 8
Answer:
A sample of 499 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
The margin of error is given by:
In this question, we have that:
90% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 90% confidence level with an error of at most 0.03
We need a sample of n, which is found when 
. So
Rounding up
A sample of 499 is needed.
